Why did you removed PETSC_ARCH_NAME variable in makefiles?

[Satish Balay]

On Wed, 25 Nov 2009, Lisandro Dalcin wrote:

> I said this before, but let's go one more time: I find --prefix
> installs of PETSc a bit useless for general-purpose installations.
> Supose as sysadmin "make install" PETSc in a cluster. She likely built
> using a C as language, double precision real scalars, 32bit integers,
> (dbg/opt?). Such configuration does not fit all applications. Some
> users may require C++, other may want complex, others may want to run
> her own codes with a debug version. Then I see VERY little point on
> --prefix builds of PETSc. Moreover, in our machines at CIMEC I
> maintain central installations of PETSc at /usr/local/petsc/3.0.0.
> This is not done at all with --prefix and "make install", instead,
> "/usr/local/petsc/3.0.0" is a HG clone of release-3.0.0.

The idea with prefix & PETSc is - one does not use the same prefix for
all installs. Here PETSC_DIR+PETSC_ARCH is the unique key from the
usage side.

no prefix mode: [only PETSC_ARCH changes]
PETSC_ARCH=build1
PETSC_ARCH=build2

prefix mode: [only PETSC_DIR - which is the prefix value, is changed]

prefix=/path1
prefix=/path2

Note: [using a different prefix path for different installs] is a
common thing to do with autoconf packages as well.  The difference
with PETSc is - for the rest of the world [of packages] - a single
install usually suffices. But for PETSc - we need multiple installs.

I still stick with the default model when installing petsc on
clusters. as switching 'only PETSC_ARCH' is more userfriendly. [and
its easier for me to install in this mode]

Satish